The present invention relates to printing and, more particularly, but not exclusively to digital printing.
Common printing methods employ liquid ink made of a pigment and an adhesive in a liquid, volatile, solvent. The liquid ink is applied to the printed substrate using a brush, pipe, stylus, rolling ball or cylinder, by sprinkling droplets such as an ink jet printer, by means of a printing pad or an offset stencil, by forcing the ink through a mesh stencil such as used with screen printing, etc.
Printing using liquid ink requires that the ink remains at the point it is applied to the printed substrate until the solvent evaporates. When liquid ink is applied to substrates that are either absorbing, such as cloth, paper and cardboard, or have a high surface tension with the solvent, such as polished metal and glass, the liquid ink is smeared through or over the printed substrate creating a poor image quality
Garment printing is performed today by screen printing press systems that are complex, inflexible, and require a specific set-up for each different print and color. First, an image file undergoes a mechanical spot-color separation process (each color is printed in black and white on a separate sheet of paper or film). Then, the image is “developed” in a long optical process, into a fine mesh (screen), which is pressed during the printing process against the media. Before printing, each screen has to be set in the proper station and adjusted with reference to the other screens. Ink is transferred to the garment through the mesh by mechanical means (generally wiping a squeegee along the screen). Garment screen-printing technology requires a special press station for each color level. Print quality is limited due to the high registration requirements between stations; hence printing resolution is relatively low.
An attempt has been made to provide a device for printing onto a portion of a substrate, such as a garment. U.S. Pat. No. 6,095,628 describes and claims an apparatus for inkjet printing pre-programmed viewable indicia onto a substrate. The apparatus is essentially a conventional ink jet printer, and is capable of creating the indicia through ink jet ink depositing upon flat or rigid substrates as a result of controlled platen movement beneath the ink jet printer head and controlled ink jet printer head movement and ink flow control by a programmed CPU. The flexible printing substrate of the patented invention is larger than the platen and portions of the substrate are draped downwardly over edges of the platen and tucked under the platen.
When printing on garments it is particularly important to limit the penetration of the ink into the depth of the fabric, which causes dull coloring of the garment.
There is thus a widely recognized need for, and it would be highly advantageous to have, a printing system devoid of the above limitations.